Why? It takes like a year and a day to make (ok, I may be exaggerating a bit) and it tastes exactly the same as the pre-cooked blocks you find in the stores. Plus, most of the flavor you enjoy from eating the polenta is from the sauce you douse it in (which of course tastes better when you make it yourself; I'd recommend yellow squash, eggplant, sauteed onions, peppers, tomatoes, spices and an assortment of grated cheese).

Conclusion to this post: unless you like grits, just buy the pre-cooked polenta.